Semiconductor Fab Equipment Manufacturing worked example

Test Stand Capacity at 99% test stand uptime availability: a worked example in semiconductor fab equipment manufacturing

What does the result look like when test stand uptime availability reaches 99%? The full calculation is worked below with real intermediate numbers. Use it when test stand capacity in semiconductor fab equipment manufacturing is being asked to take on more work and you need to know if there is room.

The inputs for this scenario

  • Units tested per stand cycle: 4 units / cycle (unchanged)
  • Available test stand cycles per period: 480 cycles (unchanged)
  • Test stand uptime availability: 99 % (raised for this scenario; the documented default is 90)
  • First-pass test yield: 97 % (unchanged)

Working through the calculation

  • Applying the documented formula (Gross test stand capacity = test stand capacity output per cycle × available test stand capacity cycles) to the inputs above produces each figure below.
  • At this operating point the engine returns 1,844 units for good test stand capacity, the number this scenario is built around.
  • At this operating point the engine returns 1,920 units for gross test stand capacity.
  • At this operating point the engine returns 19.2 units for test stand capacity downtime loss.
  • At this operating point the engine returns 57.02 units for test stand capacity yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where test stand uptime availability sits at 90% and the headline result is 1,676 units, this scenario comes in 10% above the baseline at 1,844 units.
  • A figure at this level is achievable when test stand uptime availability is genuinely sustained, not just peaked for a shift. It applies a single flat yield and uptime to every cycle; real stands have ramp losses, first-article slowdowns, and rework loops that a single-pass model does not capture.

Results at a glance

  • Good test stand capacity: 1,844 units (headline result)
  • Gross test stand capacity: 1,920 units
  • Test stand capacity downtime loss: 19.2 units
  • Test stand capacity yield loss: 57.02 units

Run it with your numbers

  • Every input above is editable in the live Test Stand Capacity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.